scholarly journals Learning Semantic Definitions of Online Information Sources

2007 ◽  
Vol 30 ◽  
pp. 1-50 ◽  
Author(s):  
M. J. Carman ◽  
C. A. Knoblock

The Internet contains a very large number of information sources providing many types of data from weather forecasts to travel deals and financial information. These sources can be accessed via Web-forms, Web Services, RSS feeds and so on. In order to make automated use of these sources, we need to model them semantically, but writing semantic descriptions for Web Services is both tedious and error prone. In this paper we investigate the problem of automatically generating such models. We introduce a framework for learning Datalog definitions of Web sources. In order to learn these definitions, our system actively invokes the sources and compares the data they produce with that of known sources of information. It then performs an inductive logic search through the space of plausible source definitions in order to learn the best possible semantic model for each new source. In this paper we perform an empirical evaluation of the system using real-world Web sources. The evaluation demonstrates the effectiveness of the approach, showing that we can automatically learn complex models for real sources in reasonable time. We also compare our system with a complex schema matching system, showing that our approach can handle the kinds of problems tackled by the latter.

2021 ◽  
Vol 16 (6) ◽  
pp. 2051-2072
Author(s):  
Maria Angeles Garcia-Haro ◽  
Maria Pilar Martinez-Ruiz ◽  
Ricardo Martinez-Cañas ◽  
Pablo Ruiz-Palomino

Online sources of information are a matter of special interest in tourism research. In particular, they are key elements in the formation of destination image. The purpose of this paper is to examine the relationship between online sources of information and destination image and to analyze the mediating role of motivation to co-create in that relationship. A research model was developed, and hypotheses were tested on data collected from 394 usable responses about the World Heritage city of Cuenca (Spain). The results show that online commercial sources have a direct positive impact on the conative, affective and cognitive dimensions of the tourist image, in this order. Additionally, this study supports the view that motivation to co-create mediates the relationship between online information sources and destination image. Finally, motivation to co-create was also found to have a positive and direct impact, in this order, on conative, cognitive and affective image. The main value of our research is that it underlines the essential influence of motivation to co-create in the relationship between online information sources and destination image. This study also provides a critical review of the existing literature by positing a conceptual theoretical framework that links three types of online sources of information (social media sources, online commercial sources and online non-commercial sources) and destination image.


Entropy ◽  
2021 ◽  
Vol 23 (3) ◽  
pp. 380
Author(s):  
Emanuele Cavenaghi ◽  
Gabriele Sottocornola ◽  
Fabio Stella ◽  
Markus Zanker

The Multi-Armed Bandit (MAB) problem has been extensively studied in order to address real-world challenges related to sequential decision making. In this setting, an agent selects the best action to be performed at time-step t, based on the past rewards received by the environment. This formulation implicitly assumes that the expected payoff for each action is kept stationary by the environment through time. Nevertheless, in many real-world applications this assumption does not hold and the agent has to face a non-stationary environment, that is, with a changing reward distribution. Thus, we present a new MAB algorithm, named f-Discounted-Sliding-Window Thompson Sampling (f-dsw TS), for non-stationary environments, that is, when the data streaming is affected by concept drift. The f-dsw TS algorithm is based on Thompson Sampling (TS) and exploits a discount factor on the reward history and an arm-related sliding window to contrast concept drift in non-stationary environments. We investigate how to combine these two sources of information, namely the discount factor and the sliding window, by means of an aggregation function f(.). In particular, we proposed a pessimistic (f=min), an optimistic (f=max), as well as an averaged (f=mean) version of the f-dsw TS algorithm. A rich set of numerical experiments is performed to evaluate the f-dsw TS algorithm compared to both stationary and non-stationary state-of-the-art TS baselines. We exploited synthetic environments (both randomly-generated and controlled) to test the MAB algorithms under different types of drift, that is, sudden/abrupt, incremental, gradual and increasing/decreasing drift. Furthermore, we adapt four real-world active learning tasks to our framework—a prediction task on crimes in the city of Baltimore, a classification task on insects species, a recommendation task on local web-news, and a time-series analysis on microbial organisms in the tropical air ecosystem. The f-dsw TS approach emerges as the best performing MAB algorithm. At least one of the versions of f-dsw TS performs better than the baselines in synthetic environments, proving the robustness of f-dsw TS under different concept drift types. Moreover, the pessimistic version (f=min) results as the most effective in all real-world tasks.


2010 ◽  
Vol 5 (1) ◽  
pp. 135
Author(s):  
Kate Kelly

A Review of: Veinot, T., Harris, R., Bella, L., Rootman, I., & Krajnak, J. (2006). HIV/AIDS Information exchange in rural communities: Preliminary findings from a three-province study. Canadian Journal of Information and Library Science, 30(3/4), 271-290. Objective –To explore and analyze, against three theoretical frameworks of information behaviours, how people with HIV/AIDS, their friends, and their family living in rural communities find information on HIV/AIDS. Design – Qualitative, individual, in-depth, semi-structured interviews. Setting – Two rural regions in Ontario, Canada. Subjects – Sixteen participants; 10 people with HIV/AIDS (PHAs) and 6 family members or friends. Methods – Participants were recruited through health care providers, social service agencies and through snowball sampling. Semi-structure interviews were conducted focusing on participants’ experience with HIV/AIDS, how they find and use information on HIV/AIDS, networks for information exchange and the effect of technology on information exchange. Interviews were taped, transcribed, analyzed qualitatively using NVivo software. Results were compared to three theoretical frameworks for information behaviour: 1. purposeful information seeking (i.e., the idea that people purposefully seek information to bridge perceived knowledge gaps); 2. non-purposeful or incidental information acquisition (i.e., the idea that people absorb information from going about daily activities); and 3. information gate keeping (i.e., the concept of private individuals who act as community links and filters for information gathering and dissemination). Main Results – Consistent with the theories: • PHAs prefer to receive information from people they have a personal relationship with, particularly their physician and especially other PHAs. • PHAs’ friends and families rely on their friends and family for information, and are particularly reliant upon the PHA in their lives. • Fear of stigma and discrimination cause some to avoid seeking information or to prefer certain sources of information, such as healthcare providers, who are bound by codes of professional conduct. • Emotional support is important in information provision and its presence supersedes the professional role of the provider (social workers and counsellors were identified as key information sources over medical professionals in this instance). Participants responded negatively to the perceived lack of support from providers including doubting the information provided. • PHAs monitor their worlds and keep up to date about HIV/AIDS. Inconsistent with theories: • Reliance on caregivers for information is not solely explained by fear of stigma or exposure. Rather, it is the specialized knowledge and immersion in HIV/AIDS which is valued. • The distinction between peer or kin sources of information and institutional information sources is less clear and relationships with professionals can turn personal over time. • Inter-personal connections include organisations, not just individuals, particularly AIDS Service Organizations and HIV specialist clinics. • Relatively few incidents of finding useful information about HIV/AIDS incidentally were described. The concept of information just being “out there” was not really applicable to rural settings, likely due to the lack of discussion within participant communities and local media. When it was discussed, participants reported being more likely to gain misinformation through their personal networks. • Incidental information acquisition originates mostly from professional and organisational sources. Participants identified posters, leaflets, and, for those who interacted with organisations, information via mail as contributing to current awareness. • The gate keeping concept does not capture all the information sharing activities undertaken by “gate keepers” in rural areas, and neither does it include formal providers of information, yet all PHAs interviewed identified formal providers as key sources. Conclusion – The findings reinforce some of the existing analytical framework theories, particularly the importance of affective components (i.e. emotional supports) of information seeking, the presence of monitoring behaviours, and of interpersonal sources of information. However, alternate theories may need to be explored as the role of institutional information sources in the lives of PHAs doesn’t match the theoretical predication and the “gate keeper” concept doesn’t capture a significant portion of that role in rural HIV/AIDS information exchange.


Author(s):  
Andrea Langbecker ◽  
Daniel Catalan-Matamoros

Sources of information are a key part of the news process as it guides certain topics, influencing the media agenda. The goal of this study is to examine the most frequent voices on vaccines in the Portuguese press. A total of 300 news items were analysed via content analysis using as sources two newspapers from 2012 to 2017. Of all the articles, 97.7% included a source (n = 670). The most frequent were “governmental organisations”, “professional associations” and the “media”. Less frequent sources were “university scientists”, “governmental scientific bodies”, “consumer groups”, “doctors”, “scientific companies”, “NGOs” and “scientific journals”. Most articles used only non-scientific sources (n = 156). A total of 94 articles used both categories and 43 used exclusively scientific sources. Our findings support the assertion that media can be an instrument to disseminate information on vaccines. Nevertheless, despite being present in most articles, the number of sources per article was low, therefore not presenting a diversity of opinions and there was a lack of scientific voices, thus suggesting lower quality of the information being offered to the audience.


1990 ◽  
Vol 12 (1) ◽  
pp. 56-65 ◽  
Author(s):  
Vicki Ebbeck

This study examined the sources of information used by adult exercisers to judge performance. Of particular interest was the investigation of gender differences. Subjects, 271 adults (174 males, 97 females) who were enrolled in a university weight training program, completed a questionnaire designed to evaluate the importance of 12 information sources in judging weight training performance: instructor feedback, student feedback, student comparison, changes noticed outside the gym, personal attraction toward the activity, degree of perceived effort exerted in the workout, performance in workout, feedback from others not in the class, goal setting, muscle development, workout improvement over time, and ease in learning new skills. Results revealed a significant discriminant function analysis for gender, with six information sources entering the stepwise procedure: goal setting, student feedback, learning, effort, improvement, and changes noticed outside the gym differentiated the gender groups. Males relied more than females on student feedback as an information source to judge performance. Alternatively, females used effort, goal setting, improvement, and learning as information sources more than males.


2021 ◽  
Vol 1 (3) ◽  
pp. 1-41
Author(s):  
Stephen Kelly ◽  
Robert J. Smith ◽  
Malcolm I. Heywood ◽  
Wolfgang Banzhaf

Modularity represents a recurring theme in the attempt to scale evolution to the design of complex systems. However, modularity rarely forms the central theme of an artificial approach to evolution. In this work, we report on progress with the recently proposed Tangled Program Graph (TPG) framework in which programs are modules. The combination of the TPG representation and its variation operators enable both teams of programs and graphs of teams of programs to appear in an emergent process. The original development of TPG was limited to tasks with, for the most part, complete information. This work details two recent approaches for scaling TPG to tasks that are dominated by partially observable sources of information using different formulations of indexed memory. One formulation emphasizes the incremental construction of memory, again as an emergent process, resulting in a distributed view of state. The second formulation assumes a single global instance of memory and develops it as a communication medium, thus a single global view of state. The resulting empirical evaluation demonstrates that TPG equipped with memory is able to solve multi-task recursive time-series forecasting problems and visual navigation tasks expressed in two levels of a commercial first-person shooter environment.


Healthcare ◽  
2021 ◽  
Vol 10 (1) ◽  
pp. 24
Author(s):  
Muhammad Mainuddin Patwary ◽  
Mondira Bardhan ◽  
Matthew H. E. M. Browning ◽  
Asma Safia Disha ◽  
Md. Zahidul Haque ◽  
...  

Unverified information concerning COVID-19 can affect mental health. Understanding perceived trust in information sources and associated mental health outcomes during the COVID-19 pandemic is vital to ensure ongoing media coverage of the crisis does not exacerbate mental health impacts. A number of studies have been conducted in other parts of the world to determine associations between information exposure relating to COVID-19 and mental health. However, the mechanism by which trust in information sources may affect mental health is not fully explained in the developing country context. To address this issue, the present study examined associations between perceived trust in three sources of information concerning COVID-19 and anxiety/stress with the mediating effects of COVID-19 stress in Bangladesh. An online cross-sectional study was conducted with 744 Bangladeshi adults between 17 April and 1 May 2020. Perceived trust in traditional, social, and health media for COVID-19 information, demographics, frontline service status, COVID-19-related stressors, anxiety (GAD-7), and stress (PSS-4) were assessed via self-report. Linear regression tested for associations between perceived trust and mental health. Mediation analyses investigated whether COVID-19-related stressors affected perceived trust and mental health associations. In fully adjusted models, more trust in social media was associated with more anxiety (B = 0.03, CI = 0.27–0.97) and stress (B = 0.01, CI = −0.34–0.47), while more trust in traditional media was associated with more anxiety (B = 0.09, CI = 0.17–2.26) but less stress (B = −0.08, CI = −0.89–0.03). Mediation analyses showed that COVID-19-related stressors partially explained associations between perceived trust and anxiety. These findings suggest that trusting social media to provide accurate COVID-19 information may exacerbate poor mental health. These findings also indicate that trusting traditional media (i.e., television, radio, and the newspaper) may have stress-buffering effects. We recommend that responsible authorities call attention to concerns about the trustworthiness of social media as well as broadcast positive and authentic news in traditional media outcomes based on these results.


2020 ◽  
pp. 106-115
Author(s):  
Roman F. Nalewajski

The need for resultant measures of the Information-Theoretic (IT) content of molecular electronic wavefunctions, combining the information contributions due to the probability and phase/current distributions, is reemphasized. Complementary measures of the state entropy (disorder) and information (order) contents are reexamined, the continuities of wavefunction components are summarized, and the probability acceleration concept is used to determine the current and information sources. The experimental elimination of the state uncertainties is discussed and limitations in this information-acquirement process imposed by the Heisenberg indeterminacy principle are commented upon.


2018 ◽  
Vol 8 (2) ◽  
pp. 9-13
Author(s):  
Vijay Kumar Bharati

E-resources are revolutioning academic libraries. E-resources available via the Internet are increasing exponentially, leading to steady increase in the use of Internet for education and research. Since past few years, free online information sources like e-journals, e-books, e-databases have increased considerably. Earlier information and knowledge were passed by word of mouth or through manuscripts and communication was a slow process. Today it is passed from one individual to an infinite number of other users through a number of media and formats which makes rapid and widespread dissemination of information possible. The information seeking behaviour of the users are also changing due to availability of e-contents. This paper discusses searching behaviour of E-resources by research scholars of Mahatma Gandhi Kashi Vidyapith, Varanasi.


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